Four of the judges defended their work at a combative congressional hearing Tuesday. They said they follow the law.

"I've seen their ailments, I've seen their pain, right in front of me," Judge Gerald I. Krafsur of Kingsport, Tennessee, told the House Oversight Committee.

Krafsur approved 99 percent of the cases he decided from 2005 to 2013, according to a new report by the Republican staff of the Oversight Committee.

Lifetime benefits average about $300,000, according to the report, so Krafsur's cases will lead to nearly $1.8 billion in benefits.

Tuesday's hearing comes as Social Security's disability program edges toward the brink of insolvency.

The trust fund that supports the disability program is projected to run out of money in 2016. At that point, the system will collect only enough money in payroll taxes to pay 80 percent of benefits, triggering an automatic 20 percent cut in benefits.

Congress could redirect money from Social Security's much bigger retirement program to shore up the disability program, as it did in 1994. But that would worsen the finances of the retirement program, which is facing its own long-term financial problems.

By the time disability cases reach an administrative law judge, the claims have been rejected at least once and often twice by workers in state offices.

House Oversight Committee Chairman Darrell Issa, R-Calif., was incredulous that so many judges would rule that initial rejections were so often wrong.

The committee's report found that 191 judges approved more than 85 percent of the cases they decided from 2005 to 2013. All told, those judges approved $153 billion in lifetime benefits, the report said.

Social Security employs a little more than 1,400 administrative law judges.

"In essence, these judges rubber-stamped nearly every claimant before them for a lifetime of benefits at taxpayer expense," the report said.

The report said some judges approved claims at alarmingly high rates as part of an agency effort to reduce case backlogs and processing times. It is often easier for a judge to approve a claim than to deny it, the report said.

Denials can be appealed, so judges must meticulously document their reasons, the report said. Approvals are generally accepted, ending the judge's role in the case.

In 2007, the average processing time for a hearing was 512 days. It was reduced to less than a year in 2012 but has since crept back up above 400 days.

There are 937,600 cases pending before administrative law judges, according agency statistics.

The House Oversight Committee is holding two hearings this week on the disability program. On Wednesday, Colvin is scheduled to testify.

In written testimony, Colvin says the agency has improved training and oversight for administrative law judges but is limited in what it can do because of budget constraints.

"Since instituting all of the enhanced quality review initiatives that I just outlined, we have observed that the number of judges with extremely high and low allowance rates has dropped," Colvin says in her testimony.

Nationwide, approval rates among judges have declined in recent years. In 2013, judges approved 56 percent of the cases they decided, down from 72 percent in 2005.

Nearly 11 million disabled workers, spouses and children get Social Security disability benefits. That's a 45 percent increase from a decade ago. The average monthly benefit for a disabled worker is $1,146.

An additional 8.4 million people get Supplemental Security Income, a separately funded disability program for low-income people.

In order to qualify, people are supposed to have disabilities that prevent them from working and are expected to last at least a year or result in death.

"I am concerned about Americans who work hard and earn disability coverage," Judge James A. Burke of Albuquerque, New Mexico, told the Oversight Committee.

"When they become disabled, they wait three years to get the coverage they earned. Lives and families are destroyed," Burke said. "I see their medical records and hear their testimony. I am trained to make legal and factual decisions. I am confident that I make the right decisions."

Burke approved 96 percent of the cases he decided from 2005 to 2013, according to the committee's report.